BRCA1 and breast cancer: Statistical analysis of the methylation profiles of FOXO3 promoter in these familial breast cancers revealed that FOXO3 methylation levels were significantly higher in BRCA1-mutated tumours, compared with BRCA2-, BRCAx- and BRCA2/x-mutated tumours (P=0.019, P=0.053 and P=0.026, respectively) (Figure 10a).